Selective excitation, coherent control, and attosecond spectrochronography of electron subshells in atomic systems

Optical field waveforms with an ultrabroad spectrum and a tailored phase are shown to enable selective excitation, coherent control, and attosecond spectrochronography of electron subshells in many-electron atomic systems. Analysis of the evolution of the density matrix of electron subshells in an atomic system driven by an ultrashort light pulse shows that the interference of different quantum pathways of electron dynamics plays a key role in the buildup of the nonlinear-optical response of such a system. Our analysis suggests a method whereby the attosecond dynamics of individual electron subshells in atoms can be coherently controlled with ultrashort laser pulses.